Photographic camera.



J. BECKER.

PNTQGRAPHIC CAMERA.

APPLICATION FILED JULY1o,19o5.

Patented Juy 1:3., 1.9M

Il? Venfol" /,a gub/L M..

Wit/1 @M60 J. BECKER.

PHOTOGRAPHIC CAMERA.

APPLIOATION FILED JULY 10,1905.

.,103,842. Patented July 14, 1914 7 SHEETS-SHEET Z.

J. BECKER.

PHOTOGRAPHIC CAMERA.

APPLICATION FILED JULY 10,1905.

Patented July 14, 1914,

'7 SHEETSWSHEIZT 3.

Fig 8 Mtr/,emga

J. BECKER.

PHOTOGRAPHIC CAMERA.

APPLICATION ULEB JULY 10, um.

Patentd July 14, 1914;A

7 SHBBT -SHEET 4 L .U al

Inman-fnv" J`. BECKER.

PHOTOGRAPHIG CAMBRAI.

APPLICATION FILED JULY 10,1905.

A y Patented Jl11y14,1914.

7 SHEETS-SHEET 5.

J. BECKER.

PHOTOGRAPHIG CAMERA.

\ APPLICATION FILED JULY 10,1905. 1,103,342. Patented July 14,1914.

l 7 SHEETSSHBBT 6.

In Ven zoq /MM /swMV J. BECKER.

PHOTOGRAPHIC CAMERA. APPLIGATioN fawn JULY1o,1995.

patented Ju1y14, 1914.

7 SHEETS#SHEBT 7.

Inl/en for Wtnezmeo JOSEPH BECCKR, F WASHINGTON, DISTRICT OF COLUMBIA.

PHoToGnArHIc CAMERA.

i To all whom t may concern provements in Photographic Cameras, of

Be it known that I, Josnri Brenna, a. citizen of the United States, residing at VVaShington, in the District of Columbia., have invented certain new and useful Imwhich the following is a specification.

The present application for atent is identied, for convenience of re erence in my other related applications, as Case K.

My invention relates to so-called. copying or enlarging cameras, or cameras which com-` prise three essential parts, to wit: a lens frame or other means for supporting av lens, an image frame for holding the sensitized surface to be impressed and an object frame for holding"tlre'illurninated original, drawing. print, negative or other object to be copiedor projected. The sensitized surface or image plane bears a certain xed relation to the image frame, and similarly the object plane bears a lixed Vrelation to the object frame; and as this object plane may also serve as image lane' the two planes may be 'ointly referred to as the image planes.

Vhcn these image planes are in roper relation to the lens, they coincide wit i conjugate foci of the lens; and. therefore, to any given relative position of lens and image plane on the one side of the lens, corresponds only one certain relative position of lens and image plane on the other side and this correct position is found by the process of focusing.

ln enlargin cameras it is not easy under ordinary con itions to secure a sharp focus by the method of' focusing with a ground glass, because the image is generally too faint to be clearly seen and because the image varies rapidly'in size during the focusing operation, and this variation in size introduces variations in distinctnesswhich are apt to be mistaken by the operator for variations in sharpness. Moreover, it is often requiredto make the image of a specified size, especially in copying charts or drawings, b'ut, after the imagelas been Shar 1y focused?, the operator will generally fini t at it is either smaller or larger than desired. He, therefore, must change the distances and focus again, and this may have to "be repeateda number of times before a satisfactory and not the best rrsultis obtained by sacrificing sharpness to secure the. exact size or by sacrificing accu- Specification of Letters Patent. Application tiled July 10, 1905. Serial No. 268,048.

Patented July 14, 1914.'

securing in all cases quickly' and by positive means the sharpest attainable image of exactly any size that may be required.

To this end my invention consists in coni necting the three frames by rods which are pivoted to the frames and to each other in such manner as to keep the image planes always in coincidence with conjugate foci of the lens.

My invention further consists in a very simple method of determining the positions of the frame pivots; also' in a type of com struction specially adapted to permit of applying such method; and, nally, my invention consists in other features, improvements, parts and combinations hereinafter described or claimed.k

All claims made in the resent application, CaSe/K, being necessarily limited to the apparatus, claims to the method are reserved for, and made in, my divisional application, Case O, which was first. filed February 9, 1910, under the Serial No. 512,842, and then reiiled as a renewed application October 3, 1913, under the new Serial No. 793,262.

ln the accompanying drawings: Figure 1 is a side view o a simple form of my invention, certain parts being broken away to show inside construction. Fig. 2 is an inverted plan of the struct-ure of Fig. 1. 3 is a diagram of another form of my linkage and of the lens with which it coperates, the focal planes being spaced as in Fig.v l. Fig. 4 is a diagram of the linkage of Fig. 1. Fig. 5 is a facevview of an adjustable form of link, and Fig. 6 is a section thereof on plane a of Fig. 5. Fig.' 7 shows a form adapted to carry' out my improved' method of properly setting the pivot bearings, the view being similar to Fig; 1, but with the linkage omitted for clearness. Fig.. 8 is an inverted plan of the same. Fig. 9 is a section on p ane :v i/'of Fig: 7, looking in direction of arrow' mj. and Fig. 10l is the same soci `tion, looking in the direction of arrow Fig. 11v is a view similar to Fig. 7, but illus- `trating the adjustment of one of the frame ivots. Fig. 12 is similar to Fig. 11, showmg the linkage and how it is adjusted. Fig. 13 is a diagram of different arrangements of my linkage. Figi' 14' shows a form of linklinks, and Fig. 15 is a simplification thereof.

racy in size to secure sharpness.

The mam obycet of my invention is to do i away with thisvtroublcsome tentative and uncertain pz'esstof focusing, and to permit of l cation of the Figs. 16, 17 and 18 show compound forms of the linkage. Figs. 19 to 2Q show a modicombination shown in` Figs, 'Z to. 12;K Fig: 19' being a longitudinal' section Fig.

, age in which the image links are the longer` with the right carriage in side elevation and the extreme right end of the bench broken away; Fig. 2O a plan of the left hand carriage shown separately; Fig. 21 a section on plane u of Fig. 19; and Fig. 22 a section on plane o of Fig. 19.

In the forms of Figs. 1 and 2 L is the lens frame, I is the image frame and O is the object frame. These three frames ma any preferred construction and a ellows may e provided to connect frames I and L and another to connect frames L and 0; but as either1 or both of these bellows may in certain cases be dispensed with it is not necessary to show them. The lens frame L is firmly bolted or otherwise fixed on the shears or ways 10 and 11 of a suitable bench having legs 12. The object frame O is rigidly mounted on a carriage 13 and the image frame I is similarly mounted on a carriage 14. Carriages 13 and 14 have tongues 15 adapted to lit and slide in grooves 16 formed on the inner faces of the shears 10 and 11. The three principal frames I, L, O are connected, cit ier directly or indirectly, by my linkage, comprising two equal links 20 and 21 and a shorter link 22. In order that the links shall never interfere in their movc ments, it is well to construct them so that the lens link 22 shall not move in the same plane as the others; and as a symmetrical construction is preferable the lens link 22 in the present form is made single and swings between the other links 20 and 21, which are made double, as seen in the inverted plan View, Fig. 2. This construction ,secures all the freedom of motion that may be desired and insures parallel motion of the carriages. The link 22 is hinged to frame L by a hinge or pivot bearing 3, and the links 20 and 21 `are similarly hinged to their respective frames by pixot bearings 2t and 2.7. These different bearings are fastened in place hy screws 26. The equal links 2() and 21, beingl virtually pivoted to the image planes, may be called the image links, and the other link 22, virtually pivoted to the lens. has already been referred to as the lens link. The four pintles of the linkage are designated by 27 and their geometrical axes are indicated in Fig. 1 by dots A, ll, A, I). Axes A, D and A may lie in any plane parallel with the direction of motion of carriages 13 and 14. As before stated, links 2O and 21 are equal. The length A B of the ima ge links 20 and 21 and the length l l) of the lens link 22 may have any values such that the difference of their squares shall be equalto the square of the focal length of the lens i) used, that is, any values satisfying the following equation:

AIiIZ--Bl)"=f2 (1) The lens 9 may be either simple or compound. Its nodal points lare indicated at N and N', and its principal foci at F and F',

be ofy F being the focus of parallel rays from the right and F the focus of parallel rays from the left. The focal length f of the lens, as well known, is the distance fr(l i l" to N, or

the equal distance from N to F', and the vertical planes through N N are usually designated the principal planes. loiut-s I and I are conjugate foci of the lens.

In order that the linkage and the lens shall coperate, the linkage must not only satisfy equation (1) above, but the pintles must be so mounted on the frames that, when the frames are in focus. on each other, the distance A D shall equal the distance l F and the distance D i shall equal the distance P F', or in symbols:

AD=FF (2) DA=PF (3) Equations (1), (2) and (3) are all satisfied in Fig. l, a.. may easily be verified, and they will also be satisfied in any other relative position of the different parts: equation (1) because the lengths of the links are i'n variable; equation (2) because A and l move equally so that if AA l) be increased or decreased by any amount, l F will be increased or decreased by exactly the saine amount; equation (3) for thc saule reason as equation (2), that is, because points.A and P move equally.

Theory of thc dcfoi'ffcf-A l) beingr identical with I) F, and l) A ident ical with F l, it only remains to show that A l) and l) A', as dimensions of the linkage, vary accordingr to the same law as the distances F l and F P of conjugate foci of the lens. ln thc following demonstration I shall first consider the lens and then the linkage.

liefcrrinfr to the upper part of the diagram, Fig. fl, in which the lens 50 is represented schematically by dotted lines, the image G of a point G is formed by following the courses of a ray G N directed to the nodal point of incidence N and the course of a. ray (l 'l parallel with' the principal axis F F. offset by the lens and proceeds after einergence along N G parallel with its original y direction, N being the nodal Yioint of emergence. The parallel ra G T meets the first focal plane in S andy the first principal plane in 'l which shifts to T in the second principal plane, and the emergent ray prc feeds virtually from T"-parallcl with S N through F,'the second principal focus. on lo G. The ligure T S G N, having all its lines parallel to the lines of ligure l F N G, is similar to the latter, so that homologous or corresponding lines of the two figures are proportional, and, therefore,

FP TS NF "SG Noting am N' F' and fr s are both @quai The nodal raytl N is simply to j", and that S G is equal to P F, the above equation yields This formula is much simpler than the usual lens formula which determines thc image and objectdistaoces from the nodal points N and N. Moreover, points N and N are generally inaccessible, Whereas points F and I4" are easily located and can be used, as will be seen later, to greatly simplify the afl'ustxnent of my camera.

he theory of the linkage of F ig. l Will I follow directly from the theory of the linkage o1 Fig'. $3. The linkage of Fig. 3, thou h less simple, most clearly illustrates all tie principles involved, because the correspond ence. of its two sets of Newtonian space elemento P l", F l and A D, D A is direct and mest easily understood. The lens 50 is the same as in Fig. 3, is likewise represented diugrammatically in dotted lines, and, whatever its form, is fully determined for the present purposes bv the position of its nodal. points N and N and of its principal foci F and l1". At D and D in the principal focal planes F D and F D of the lens are ivoted equal lens links D B and D B. l t A. and A in the image planes are pivoted equal image links A B andA B. The joints B and B 0f these two pairs of links are connected by a link B B equal in length to the distance D D to form a jointed parallelogram B D D B. The lens is thus connected to image plane P by a air of links D B A. and to the conjugate p ane P by a similar pair of links D B A, and either pair satisfies e uation (1)'above. By

considering triangle B D we see that BW2 BTP KM also that BD w BMz MD A'n' s55 (7) i has, therefore.

New, assuming any value' for the object distance P F, the image distance F P by the lens formula (5) above will he (fz-f-PF); and, assuming the same value A D equal P I" in the linkage, the distance A D by the linkage fm'nlula (7) will also be (fE- l-PF). The linkage will, therefore, always hold plane A in coilnfideiure with the oonjugate focus P of l).

By leaving the lens 50 and the innige planes P and P', as in Fig. link B B, the triangle A B l,) may be shifted to the right and triangle A B ll may be shifted to'the left 'Until links l1 D and B l) coincide and Murge into one link B D, as in Fig. 4, where the points A rand A' of the linkage are connected to the image planes by bars m and m. The length of bars m and m inav have any values, except that their nlgebrahl um nnu't equal the distance D D of tiig. i. or the jlis tance I*` F in the lens, that is. equal lo twice the focal length of the lens. plus thtl distance N N between the nodal points. But Fie: 4 just considered has the same horizontal din 3 and removing mensions as Fig. l. and is the diagrammatic representation of Fig. l. lt therefore, clear that 1f a properly lighted olriect he mounted 1n one of the two focal planes l or l of Fig. l, its imago 'will he seen sharply focused in the other local plane, and that this will be .so-in all posztn'ins oi\tlu mechanism and frames. lf the 'trames are nlovcd, the diameter of the image will, he seen to increase or to decrensc. accordingl to thc eli-f rection'of the mot-ion, but its sl1argu1cf--s`wvill remain ccnstant, except in so far as sharp ness may he nllectcd by the scale of reduc tion or enlargement. ln the proportionsl ote Figs. l and 2 the diameter ot' the image may.' be increased up lo over three times rT/'L/,l the diameter ol' the original. and it may he decreased'down to less than onethird (f2/7), giving a range of 4 to 49 or' exceedingr l to l2, that. tht` smallest innige has a diameter less than one-twelfth of the largest.' These arc about the limits ot' the device as shown in Fig. l, but the range can be increased. if desired, by making the Ways l() and ll longer and lengthening the links QG, 2l and 22 to correspond. The operator, knowingr that the image is sharply focused, nothing to consider hut size, if size be ot' importance to him. lle may control the size by direct inspection or measurement of the image, but to avoid this l l I preferably use a scalc.- Scales have hcretofore been used in enlargement cameras, mainly for the purpose of focusing: but as I focus mechanically I have devised un iniproved scale that is specially adapted to co- 133 operate with my linkage.

Scale of enlargement and'. reduction foftors.-"1`his scale is marked in fixed relation to the lens, in any convenient place.. and in the present case on top of the bench or on 1&0

it t) the outside edge thereof. To save additional illustration it is repeated in Fig. 1 on the inside face of rail 10. The graduation comprises a graduation 1, 2, 3 at the left for the object frame O and a similar graduation 1, 2, 3 at the right for the image frame l, and the numbers'indicate. enlargementfactors. 'lbus frame t), as seen in the figure', registers with enlargement. factor 2, which means that (l ll is twice G' ll. Frame l must; then register with reduction factor le of its scale. as seen, to indicate that il ll is onehalf of (i Il. The divisions of this scale, that' ie, the divisions of the reduction factors, are small, crowded and irregular iid as the linkage permits of dispensing with one scali' I prefer to do away with all graduations below 1 on both scales and to set the frames in all casi-s, whether for enlargement orfor reduction. by means of the enlargement factor. That is to say, either scale sets its fanie for enlargements and sets the ol'iposite frame, by means of the linkage, for the corresponding reductions. The two enlargement scales, therefore, act :is a combined enlargement and reduction scale. This is a great advantage, especially as the steps of the eiilargen'ient scales are uniformi: that is to say, the distance l to 2 equal the distance 2 to Il, and either of thesey is equal to the fecal length of the lens and the steps may be uniformly divided for intermediate values. The principle ot' the enlargement scale can -be demonstrated by where the enlargement factor Diagram ip Gl TNV GS lili defer/Nac f whence and in similar niauner it can be shown that PIAF/ 1f: DIA! n rl`he distances for the enlargement factors are, therefore. seen to vary in direct proportion to n and the distances for the corresponding reduction factors` vary in indirect proportion; the first scale being uniform and well spaced, the latter irregular and crowded. lVith this improved scale and the linkage, the operator pays no attention whatever to the innige. lle directly inserts his sensitive paper plate or film and selects his factor of enlargement. or reduction, say, for instance, 2%. lf the factor is an enlargement factor, it is the image frame l, that he sets at 2;, and if it be a reduction factor it is the obJeet frame t) that he sets at Then 'lic exposes and without ever having Iseen the image he knows that he has secured the .sharpest attainable image of exactly the size desi red.

In copying drawings or charts it is necessary to tirst make a negative form which the final positive prints are made, and to reduce expense the negative is often made very small. My device is Well adapted t malte both the negative and the positive, and in this case the combined enlargement and reduction scale is a ver;Y great convenience.

lf/,ii/efmcnfa.--lf lensescoiild easily be. made of a 'certain focal length. there would be ne dilliculty in manufacturing the device :is just described. lit is well known, however. that even the highest price lenses are never expected to be of exactly their intended focal length. l'n lseinbliiig the linkage. and camera elements .a the factory il is. therefore. ne sary to allow for departures that may be present in the focal length of the lens. A niin'iher of different methods ma)7 be followed. The simplest, to be given later, requirespecial features of contraction not present iu the structure of l"igs. l and 2, and 1 shall. therefore, first .give a method that can bc applied io the structure of Figs. 1 and i. Bearing 23 is supposed to be fastened in place, that is,

.vherever convenient, but bearings 24 andr 25 are ,supposed to be uiin'ioiinted. lf hearing 23 he mounted midway between tht,- principal planes` N, N of the lens, the other two bearings will have to he at equal dis: taiices from their respective image planes and the. construction will be symmetrical; but if hearing 23 he mourted closer to one of the iwolfocal planes F, F than to the other the structure will he iiiisyniinctrieal, as in Fig. l.. Syn'irnetnv not essential .in my device. and, therefore. the hearing 23 is preferably mounted. in the most conveiiient place, which in the present instance is directly on the lens frame itself, shown. Bearing 2?, therefore, being mounted: first, measure the focal length ofthe lens by any known method; second, construct the linkage to satisfy equation (1); third, temporarily clamp one of theframes (l or I to the bed and mount a test object in its image plane, and sharply focus the other frame, clamping it also. Fourth, measure any line G H in the object. and the. length G.H of its4 innige to calculate fn, the factor of en.- largen'icnt; fifth,\moiin't and fasten bearing 24 so as to satisfy equation (8); sixth, fasten hearing 25 to satisfy equation (9); seventh, mount the linkage which should now fit exactly. Theseeond step above can he left, to the last. That is, bearings 23, 24 and are all fastened as indicated above;

Athen links 20 and 21 are mounted and the,-

distance B D is measured to construct link` l?" The short link 22 may also be made" is thneade near one 'end to receive a screw le 31 and part 305 is similarly threaded to receive. a screw 31. Slots 32 and 32 permit the parts to slide upon each other when the screws are'loosened. When link 22 is thus made adjustable. it is no longer necessary to measure the distance B to D, as proposed above, for the screws 31, 31 are simply loosened enough to permit the short link to extend or contract; freely so it may be in- 107. Frame O serted and .mounted in piace and then firmly clamped to thelength that it has autoiixatically assumed during the mounting operation.

The adjustment might be made'in the two long links or elements A B and B instead of in the short link or element B D, but adjustment of the short link is simpler.

Improved forms-It is seen that the manufacture of accurately operative devices of the form of Figs. 1 and 2 involves considerable trouble and is, in fact, impracticable, even when the adjustable lens link of Figs. 5 and 6 is used. I have fortunately dis covered a method of adjustment that perl mits of dispensing with all measurements, dispensing even with thel measurement ofthefocal length of the lens; but this method involves a. novel principle of construction which consists in so forming the device that the bearing of axis D shall admit, or be admitted by, either of the other bearings in such manner that the axes A and D or the l axes A yand D may be brought into exact coincidence. i

Referring to Fig. 1, it Will be remembered i that, when the apparatus is in perfect adjustment, the distance F P is always equal to D A" and that the distance F P is always equal to A D. If F P could be reduced toV zero. D A would also become mit, and if F P could be reduced to zero, A .D would ben come /n-i'l. 'That is, the hinges would interpenetrate so as to have their axes in coincidence. But. when F P is m'Z, frame 0 is in focus on parallel rays from the right, and, when F P is nil. frame I is in focus on parallel rays from the left. My method 4of adjustment. therefore, consists in first fixing I 'une cf the axes. say. axis D. and then using it as a guide for setting the other two axes, by focusing on infinit-y.7 A structure that vermits of applying this method is shown in i"igs. 7, 8. 9, 10, 11 and 12. The object frame 0', the image frame I, the lens frame L and thebcnch comprising shears 100 and 101, are all substantially as in 1, but the groove or slide way 102 formed in the shears is continued Without obstruction under the lensl frame L. To insure a clear passageway for the carriages 163, 104, Liz-ame L is, furthermore, raised on blocks 105, 106., which are fastened to `rails 100 and 101 by screws is rigidly mounted on its carriage 103 by means of a block 108, and l frame I on its carriage hy a. block 109i. The i Y is thus rinly and accuratelglxed in I free.

bearing for the lens axis D is simply formed by a bore 110 in shears 100, 101, as best seen in Fig. 7, to admit a pin 111, best seen iny Figs. 11 and 12. T1 object axis A and the bearing 113 for the image axis C may be exactly as in Fig. l, but* I preferaby mount them as seen in Fig. 8; that is, I form in bearing 112 a pair of .slots 114 to admit screw bolts 115. Bearin 113 has similar slots 116 to admit bolts 1.17. The linkage comprising the image links 120, 121 and the lens link 122, 123 (Fig. 12) is exactly as in Fig. 1, but with the lens link adjustable as in Figs. 5 and 6.

Having mounted the lens 118 in frame L', the adjustments are made as follows: The links 120, 121 and 122, 123 are removed so as to leave the structure asin Fig. 7. Frame O is then slid np, as in Fig. 11, t0 brin the bore of its bearing 112 in alinement with the bore 110, and pin 111 is inserted to secure perfect coincidence of axes A and D, as indicated in Fig. 11. Screws 115 are now loosened and frame O is sharply focused on a distant test object to the right. that is. on parallel rays from the right. This brings image plane P into exact coincidence with the principal foral plane F of the lens. Screws 115 are then tightened and axis A thus firmly and accurately fixed in proper relation to its image p ne P. Pin 111 is withdrawn and frame is now ushed in to bring the bore of its bearing 115 in alineu nient with bore 110, and pin 111 is again inserted to secure perfect coincidence of axes A and D. AThe bearing 113 is loosened, frame I is then fociised'on left infinity to bring its image plane P into coincidence vwith the principal focal plane F of the lens. Screws 117 are then tightened and axis A proper relation to its image plane The linkage is nou' mounted as indicated in full lines, Fig. 12, that is, with the lens link entirely open to leave the carriages 103, 104 perfectly Frame O is now set in any position, say. in the position seen in Fig. 12, and is preferably clamped in any suitable manner. A test object is mounted in its image plane P and frame I is then sharply'fccused on P and similarly clampixl. The lower member 123 of the lens link is now turned up against member 122 and these two members are firmly secured together by inserting the screws 124. The linkage now satisfies equa tion (1) because the product A D. D A

by equation (6) is identical with F. F 1 or equal to f2." The device, therefore, satisfies all the theoretical conditions and frames I and O may be unclamped for use.

As it may be inconvenient to have test objects at both right and left infinity, it will ic bearing 112 for the los , as made in Figs.

'Iltlly Camera,

by employing generally be easier to turn the apparatus end for end and focus on only one well selected distant object, and if any difficulty be experienced in linding such an object, the focusing may be done on the parallel rays produced by a collimator. If special relinements be used in focusing to adjust the camei'a,`tlie camera will give the same degree of accuracy when used to make exposures.

No measurements and no calculations are required with the apparatus of Figs. 7 to 12. Its different parts are constructed and simply assembled read;r for adjustment, and the adjustment is made by only three focusing operations, such as made with ancrdiwithout paying any attention either to size of the image,or to focal length, or to any other dimension. The apparatus 7 and 12 may, therefore, be put on the market without a lens, with instructions such as those above, for correctly 'adjusting it. As it is better not to make the device excessively large and to make the latitude of adjustments small, it is preferred to' manufacture the device in several sizes corresponding to the focal,

lengths of ob'ectives commonly used in hand cameras so t at the purchaser may use his own camera lens. Then either frame is focused on infinity it corresponds to the zero of its graduation of enlar ement factors, as may be seen by making t e factor n equal to zero formulae (8) and (9). is shown marked in Fig. 1l-for frame O', although it can never serve after the linkage has been mounted and adjusted except `as an aid in making the graduation. The

graduation, however, if required, '.nay so easily be made, by direct measurement of the image after the linkage has been mounted and adjusted to' focus, that no otlieil method need be used.

Mod/fied form.-By referring to Fig. 3, it will be seen that the lens axis D is connected to the image axis A'by a crank and pitman connection or two unequalL links which form a triangle A B D, and that the lens axis D is connected to the other image axis A by two similar unequal links formanother triangle A B D; also that the bases A D, A D of these two triangles are variable and are caused to vary together means to compel the angle a opposed to t e longer link in triangle A B D, and the angle a' opposed to the longer link in triangle A B D' to remain supplenientary, that is, to always form two right angles when added. The angles b and b' opposed to the shorter links, therefore, 'also vary, but remain equal. A great number of other types may be derived either with or without shift, by changing the position of these same triangles on their base lines.t n

j Geometry." published and copyrighted by posii Hai-per and Thus, as seen in Fig. 13, triangle A B D may. without any change in length or This zero' tion of its base A D, be set in either one of the four different positions indicated by 1, 2, 3 and 4; and triangle A B D may similarly be set in 'four dilferentlpositions 1', Q', 3', 4. The positions referred to by uneven numbers are those in which the lens link is the shorter link, and the positions referred to by even numbers are those in which the lens link is the longer link. Any one of the four triangles on base A B may be used in combination with any one of the four triangles on base Al D; and. furthermore, any numberv of the six remaining triangles shown may be added 'to the combination, if desired. Thus by takin 2 and 4 the linkrage of Fig. 14 is forme Here the link G0 is produced as a lever to V and joined to B by a link (S1 equal to D D to form the parallelogram B D D V and compel the angles band b to remain equal. By a shift of the triangles, su'cli as that made to pass from the type of Fig. 3 to the type of Fig. 4, this linkage of Fig. 14 becomes the very simple form shown in Fig. 15, which may be considered as typical of those forms of the linkage in which the image links are bothshort links, while Figs. 3 and ,4 are "typical of the forms in which the image links re both long links. A rm in which both long and short linksare connected to the same axes is shown in Fig. 16. This is formed by taking triangles 2,'3, 3 and 4 of Fig. 13. This linkage may be considered as the linkages of Figs. 4 and 15 combined to cooperate, and it has the advantage tliat its pivot axes A, and A will remain iii perfect alineinent without a slideway because point A', for instance, is connected to points A and D by truss connection and is thus held in nlinement with them, so that no useless side pressures are put on the slidesA and very smooth action is secured. To permit. of clearly distiiignishing` thc two sets of linkage, one set isshaded with horizontal lines.

liy taking triangles 1, 3, 1 and il of Fig. 13 the compound linkage of Fia'. 17 is formed. and by duplicating the linkage of Fig. l5. and reversing about an axis Vperpendicular to A A in the plane of the drawing. the linkage of Fig. 19%' 'is formed. J

The forms of v17 and'lS are both old :is elemcnts in .straight line or sii-called parallel motion mechanism. Fig. 17. for instance. comprises six of the .seven links used iii Peaucelliers working beam. in the special forni of it shown in Fig. 413, p. 501, of Klein translation of Weisbach`s .le ffiaiirfs o f fligimv/if'iijj, Vol. lll. part l, section ,1.New York. 1883. See also the four dii'vrfiiil straight line linkages in Figs. 24S {1).2l3 (2i. QG (2) and 26 (M on page Brothers, Xew York, 1896;

noting that any linkage such as that of' Fig. 26 (l) in which the-constant product vectors O P and() Q, are similarly directed, must have one -o'f such vectors reversed, as by pantographic modification Fig. 2G (i), to be. usable as focusing gear.

All the linkages shown in the drawings merely serve to form a 'crank and p-itman connection between` the lens and 'either image plane and toca'use the. two connections to move so* that the angles a and a opposed to the longer links shall be and remain supplementary, this being the fundamental principle of my invention. Any

` linkage, therefore, containinglinlcsithat satisty these conditions may be used, provided' the links thereof that' correspond .to my crank and pitman are proportioned" to sz1tsfy equation (l). However, Aforms `of the type s'l'lown' in 15, 16, 17 and -118 are not directly applicable to the arrangements of 200, 201, connected at their-ends to cross Iiigs. 1 and 2 or' to that of Figs. 7 to l2 be 'ziuse a part of these linkages would be interfered with by the lens frame. To avoid this difli-cul'ty, Imount them on either side of the camera; or horizontally on top and onth'e bott-om of the camera. lVhen mounted on' the top' or on the bottom, one set isv sufficient. An' arrangementwhich is suitable` 'for anyx side of' the camera is shown in Figs. 19: to 22g-as applied lto the' bottom. ffhebed here `comprises two parallel bars pieces which serve as' feet. At the lnid llotlle bars' have a solid cross piece 204 fjvhieh isz'idnpted 'to .supporti the len-s' pintle A 205 which is runde with an integral 'collar or shoulder QOtand held solidly by a nut 207 nt. its upper end. At thelower .endthe -j'iiu 205 husa (jotteror'pin bymeuns of which the-linkage is'to be held'fou the. '-piu. A i :t -bridge 'piet-e C!) upon Wl'iith'is firmly (lose 'to bar 204e is riifidly fastened screwed' the `lens frame L3 as'shown.- As Seen in Figi-"7 `ringe are lextended to form .bearings 2522 for the image pin which is' .-eld in place by a Cotter or pin 224e. Through the body of the carriage 220 is formed a large rectnugular openinf.r 225. Fig. 20, the longer walls of which act as n. guidewny for n block uponw'hich is firmly mountedA the object raine'03. This block carries n cap screw whiehjis threaded into n. A cross-bar 228. 'The frame V(li-may be set where desired on. carriage 2:20by -first Y Y thislnridge piece is intended Ato form a space .under the lens 'frame to v leave the way clear for the carriages '220,

Figs. 7 to 12. The only difference to beA noted between the adjustments of Fig. 7 those of Fig; 19A is that in Fig. 7 the bear-.

lng is adjustable on the slide, while in Fig.

l19 it is the' image frame that is adjustable on the slide.

Infthe structure of 19 to 22-any one of the linkages shown in the drawings may Its parts .231 to 238 correbe used. If that' of Fig.-17 be used its two lensulinks should be made adjustable and the linkage may evidently be mounted and odjusted as explained [in connection with Fig. 12.

,In allv forms shown the lens frame isA the stationary frnme,but it will oe understood that either of theixnage frames may be staci ple. Y

tionary instead without any change in prinr' ,I l '95 My contributions to the artjn generalV terms may be summed up as follows:

(a) I am the first to devise pa focusing mechanisurwhich 4is adjustable for use 'with different lenses'and which. contains the particular adjustments that, (according to the Gaussian theory 'of lenses, are necessary :and adequate to permit of su'rely securing ,the highest available efiicieney of any lens that is to be vused'with such niechanism.

Y- (1 4) My focusing' meelmnisunf composed solely of parts asseu'ibled in purely pniotal relation, the first and-ouly one overproposedy that does notl cont-.iin slides in addi-..

tion-.to the main slide-ways or rail-.bed of thecamera. c

.(ff- My can-1era is the first to be ad] usted and regulated ready for use without paying any attention to the nodal points, or to a :n

sri-called optical center and 'without even knowing 'the focal length of the lens used.

General {Bauwerks-Note 1. The two free longitudinal adjustments provided inthe frame connections Fig. 8 or F ig. 19)' permit 'of separately and inde `.i1'.lently satisfying equations 2 vand 3,:- und the third iudepe-ndent adjustment (Fig. (E) lprovided in the mechanism Vproper permits of independently satisfying equation '1.

Note These three entirely reeandindependent adjustments, or 'their equivalents,

'itis are useful inany conceivableform of focusing mechanism and they are xnd1spens-4 able if the higl'nest available eiciency 0f thqfib' lens must surely be attained.

. closures, I

MJV'XN') 'OP four times the iosaliiei'igth. I "f the? lef-1S Plus the -internodal distance N gramn'iatically by. Professor Elie in theV Journal-cle Physique, Paris, 1880, pp. 162 to 104; also that this project is entitled `an articulated mcc'hanismf7 but 1 believe that it cannot possibly berealized withoutintroducing pin and slot or similar sliding con! nections.

Note 5. I am aware that pin and slot or radial cam focusing mechanism is shown in inGerman Patent, 162,004.- of" '1897to Carncntier, and that this mechanism determines two co-varying constant product and-valined space elements BO and O B' (Fig. 2); but this patent does not explain how tornake allowance for the internodal'space N'Nf, and refers instead to aso-called optical center.

Note (3. I am aware that"-l5`loqi iet'ifn the Bulletin des Sances le Za Socit des Sciences Ze Nancy for May, 1'898," pp. 10 and' 11, (copy at Library of Congress)l proposes to vconstruct the Carpentier.icameraffby lo eating the Carpentier"lexis'pivot midway be- ''tiveen the two principal ornodal planes N Vand N' and by'mountingthe end 'frame pin- Itles at a distance'equalto'fpli1s all of N Nf,

from their respective image planes', and that this rule of l"loquet`does=make" proper al-I lowance `f(`` the intermodal -s'p'e 'NfN/but the Floq'uet rule is not sufiicientlyfgeneral for my purposes, as I lmake. noatten'i'pt whatei'ergexcel'it in my vtheoretical form, -Fig- 3,

to placeiny leiis pivot or'lensjivots 'in anyv definite or' eren: known" longitudinal rela-.A

lish'Patent No. 12,734'lof (lineM,15.19, to line' 2, page '10) refers to 'thep'ossibility 'ofso designing his apparatus'y that'V the focus-` ing `mechanism and connecti'iigfpoints 'asa' whole shall be 'shifted longitudinally' with' relation to the three frames' 0,11, I; biit,'ac

cording to Cook (lines 56,57, p. 9),' af tersuch shift'has'bemande,- the-"total distance between the 'image planes tinu'st -be equalto four times the focatlength'of the' lens,v whereas, in accordanc-iitli" myi disthis same distance"should 'he Notie 8. I am aware that Athe diagonal advjustments of the cnd fra-me pintlesp,

and (I, q of Cook (Fig. 8) in guideways tft and s, .s have longitudinal components, which are parallel to the. lens axis and which constitute longitudinal adjustnients; but such longitudinal adjustments in Coqlr are, and in any case must be, equal hence not iiidependent because, as 'correctly statedhy Cook in lines 46 to 40, page t), it is necessary that the distances` of pins p, 79,@ ndldig. 8, from the transverse fulcrlim plar'ieof'b, Fig. 8. should each be equal to the focal length f of the lens when the apparatus is at' unity Note 9. I am aware that Frcot published at Nancy, France in the Bulletin de la S0- czt Lorraine de Photographie for May, 1898, pages 95 to 115, a comprehensive article on focusing gear (detached copy atthe Library of Congress in bok marked Frcot- Chambres drl grandssement No. TR475.F8) which discloses or refers to adjustments that are to be distinguished rominine, as follows: I am aware that Frcot shows nFigs. 1 and '2, page 102, a longitudinal adjustment of vhis object frame pintlel Gr (referred to in lines 6 and 7, page 103; lines 18 to'24, page 104, and linesl to 3, page' 107) and that he mentions a' longitudinal adjustment of the image frame connection in lines .25 Vto 31, I

page 107, but in the latter passage he ex- 'eludes any other longitudinal-` adjustment. Tlie full oliicial card catalogue title of this Frcot document is :,"Frcot, G., Mthode simple pamf tablir les lments de pluseurs .ig/.gtf'r/L'efxl mcaniques au moyendesquels on peut transformer V volont-:fume chambre dagrandissewwnt ordinaire en une Achambre: `dag/ra'mhls.sement toujours au p'on automat/guem-'evnt quel que .soit lfagr'mdzssemenf. -Xote10 Iam awarefthat Claudet in 'Thx Journal' o the Photographic Society of Londomo'f arch 15,-1861'vo1ume 7, 1862;'pages page'VI as R'. H; Bow) in the British Jwj nal of'jhotpg'aphy, of December Y1, 1865,

volume 12, London, 1865, page' 608, 'lines 18 -to 453, disclose an infinity method of establishiiig a :focusing scale, but such me'thod is not -used 'as in my camera --or. determining the dimensionof a constituentelement of automatic focusing mechanism:

Note 11. I ainaware thatfregulation of the` Carpentier-camera of` German? Patent- 102,00l1is alluded t o in the'00mpt8'Rendus,

Paris-18ste, Noi. 126,. page 895,; 1iinesf 15 'to 23; also` in the Scientific'Ameicangsupple ment, New York, 1898, page 19170,' column` '2, lines 18 to 9 from the bottorn;fbut'si1ch regi'fr ulati'on does' not necessarily comprise adjustments, and-it is, furthermore, confus'dby reference to13 different lens centers; .where- 215,1 use only 2,' to` witz the nodal. points N and N'.

'connections' between such relation to Vhat l claim as my invention and desire to secure by Letters lateut ig 1. The combination with a photographic camera. comprising' :i leus support, nu' image support andan ol'iiert support'` and ways adapted to guide two of said supports with relation to the third; of mechanism tor eo1i net-tingr the said three supl'orts to compel two of them to more simultinieodsly with relation to the third.said mechanism considing in an assemblage of pivoted rods.

2. The combination with a photographie ramera. comprising a lens support, an image support and an object support, and ways adapted to guide two ot' said supports with relation to the third; ot' meenanisin t'or connecting the lsaid three supports to-|ompel tiro ef them to more .siinultaiwously with relation to the third; said mechanism consisting in a crank and pitnnin (zonnet-tion hrtwetn the lens support and either image ,support to form two variahle triangular supports; and means for causing the angles of such triangles that are opposed to the pitineii or longer members to he and remain su'iplementary throughout 'all variations ov the said triangles.

El. The'combination with a photographic camera, comprising a lens support, an image support and an object support. and Ways adapted toguide two ot' said supports with relation to the third; of mechanism for connecting the saidthree supports to compel two of them to more siinul .|1eously with the third, said mechanism consisting in a linkage comprising three rods. one pivoted to the lens support, the seel td to the image support and the third to the object support and a pi tot connecting the three rods.

1. The combination with a photographie camera, comprising a lens support, au image support and an object support' and sli'dcways adapted to guide two of .said supports with relalionto the third. of a pintle or pintle hearings mounted in fixed relation on ea Jh one ot' the said three supportsin a direction perpernlir'uhir to the direction of motion in fh/ e said slideways, and means for freely adiusting tfworof said pintles or pintle hearings on their respective supports in the direction parallel to the said slideways; also foynsiimY mechanism for connectingr said p'intles or pintle bearings.

The combination with 'a photographic camera, comprising a lens support, an image support and an object support, and ways adapted to guide two of said 'supports with relation to the third; of mechanism for connecting the said three supports to compel two of them to move simultaneously with relation to the third. Isaid mechanism consisti-ng in a linkage comprising three rods1 to 'the image support i l i l l one pivoted to the lens sudpport, one pivoted an the third to the object siriipport; a pivot connecting the t'htee rods, .an means for adjusting the. length of the lens link.

6, The combination with a photographic camera. eomprisin a lens support, .lan image support and an o ject support, und ways adapted to guide two of said supports with relation to the third; of a bearing mounted on each of these 'three supports; said earings being adapted to have their axial ines l'irought into coincidence by moving the Said supports in the slideways also focusing lnecianism mounted in and connecting thc nid hearings.

T, 'The combination with a photographic vaincra. comprising a lens support, an image support and an object sup ort and Ways adapted to guide two of sal supports with relation to the third; of bearings mounted t.,

nu each of these three supports, said bearing.`v being adapted to have their axial lines brought into coincidence by moving the said supi'iorts in the slideways, and ineens for adjust-ing the relative position of two of said supports to their respective bearin s also focusing mechanism mounted in an connecting the said hearings,

8. The combination with a photographic camera, comprisingr a lens support., an image support and an object sup Ort, and Ways adapted to guide two of said) su ports With relation to the third; of mechan sin for connectin the said three supports to compel two mg them to move simultaneously with relation to the third, said mechanism (mn- .sis-ting of rigid parts connected to each other in pivotal relation.

9. The fomhination with a copying or enlai-ginev ramera comprising a support for an ohjeet plane. a support for a. lens, and a support for an image receiving plane; also a lied or slidci'ay for said three silpports to permit. of displacing them as required to L'eeure imanesl of different sizes; of focusing mechanism havingr three inde/ pendent connertions with said three Supportsl to cause tno of vsuchsi'ipports to move with relation to the third :.aud adfustments in at least two of said three independent rigid connections to provide free adjustment ot' sut-h adjustable connections in the longi tudiual direction parallel to the slideway of the camera bed.

lll. JThe romhination with a Coliying or enlarging` camera comprising a support for an object plane, a support for a lens.' and a support for an image receiving plane; also a hed or slideway for said three supports to permit ,ldisplacin them as required to secure images of di erent; sizes; of focusing` mechanism having three independent connections with said three supports to causa two of them to move with relation to the third; and adjustments in two ot' said three independent connections to provide free ad justment of siieh two adjustable connections in the longitudinal direction parallel to the siidew'ay of the camera bed, so that the tlnad independent connection may be made longitudinally `arbitrary and invariable, regardless of the proportions of the lensl to be used in the camera.

11. The combination with a copying or enlarging camera comprising a support for an object plane, a support for a lens, and a support for an image receiving plane; also a bed or slideway for said three supportsy to permit of displacinv them as required to secure images of ditierent sizes; ot' focusing mechanism havin lthree independent connections with sai( three supports to cause two of them to more ywith relation to the third; and adjustments in at least two of said three independent connections to provide free adjustment of such adjustable connections in the longitudinal direction paralle( to the slideway of the camera bed.

il The combination with a copying or enlarging rana `a comprising a support for an object dane, a support for a lens'. and i support or an image reeciving plane; also a hed or slidewai for said three supports to permit of displacing them as required to secure images of different sizes and focusing mechanism havin" three independent, connections with said three supports to cause two 0f them to move with relation to the third; of two independantr longitudinal ailjustments in said eonnections and. one independent adjustment in the said mechanism.

18. The combination with a copying or enlarging camera. comprising an object plane, a support for a lens. and a support 4or an image receiving plane, also a hed or slideway for said three `supports to peimitof displaein r them as required to entre images of di erent sizes; of focusing mechanism adapted to produce constant product space elements P F and 1" P with means to permit of reducing either of such a support forV constant product space elements to zero 'alue ll; The combination with a copying or enlarging camera comprising; an object plane, a lens` and an image receiving plane.` also suitable supports and a hed or slidenuy for said three supports to rpermit of displacingr them as required fo secure images otvditl'erent 4sizes; ol focusing mechanism with means to permit of reducing either of the cti-varying Newtonian space elements of Such mechanism to zero value.

l5. The combination with a 'ihotogrraphic camera comprisingr a support' tor an object. plane, a support t'or a lens. and a support for an image receivingr plane; also focusing mechanism haring three .separate connec tions with said three camera supports to cause two of them to more with relation to the third; of longitudinal adjustments in two of said three separate connections to permit ef making due allowance for all possible Variations in the extent, sign and location of the imernodal spaceN N of the lens to he used; and an adjustment in the focusing mechanism to perl". it o" naking due al lowance for all possible variations in the focal length of the lens; each of said three adjustments being independent of the other two.

1G. The combination with a photographic camera, comprising a lens support, an image support and an object support, and ways adapted to guide two of said supports with relation to the third, of a pintle or pintle bearing mounted on each one of the sai( supports and extending in a direction perpendicular to the direction of motion in the said ways, and means for adjusting two of said pintles or pintle hearings or their respective frames in the direction parallel with the said ways.

In testimony whereof I have `signed this specification in thc presence of two subscribing witnesses.

' JOSEPH BILGKER fitnesses z MARY E. Vlowiiaii, BENNiz'rr Jones.

upon the application of Joseph Becker; of Washington, D. C., for an improvement in Photographic Cameras, errors appear in the printed' specification requiring correction as follows: Page 3, line 18, after the word camera, insert the following: Ejuatz'on (4) is referred to by French aut/lors. 0n optics as Newtons formula, a practice t/lat it wtl e convenient to foltow in t/zzls Wecz''caton, and t/at has its justt'lcaton, as 'will be seen on referring to page 8, ease 4, and Fig. 7 ofNewtons 0ptzccs7 (sie), Zanden, 1704. u .4 .l7e co-'varyz'ng comtant oduct cizlstances PF; FP' may accordingly be designated as t/e Newtonian space nts 0f the leds' while corresponding distances z'n t/ze meekanem, suc/L as AD and DA', Hg. I, w 11e/i must, respectively, remain ual to PFU/nd FP y equations 2 and 3, may e deszgnated as the Newtonian. space ments of the wwe/lanzan. same page, line 56, change .DA] to DA; same page, line 68, change to same page, line 7l, change to page 4, line 66, for the word form readfrom;

.page 6, line 33, after the word zero insert the' word in; and that the said Letters Corrections n Letters Patent No.'1,103,342.

Pate `should be read with these corrections therein that the same may conform to the record of the oase in the Patent Office.

Signed and sealed this 4th day of Augus't, A. D.; 1914.

[SEAL] J. T. NEWTON,

Acting Comms'ssaner Qf Patents.

It is hereby certified that in Letters Patent No. 1,103,342, granted Juljr 14, 1914, upon the application of Josepliecker, of Washington, District of Columbia, for an improvement in Photographic Cameras, errors appear in the printed specification as follows: Page 8, line 3, for the word of rend or; same page and line for the word or read of; also in the correction sli-p dated August 1914` line 1Q, underscore the words Newtonian Space elements of the lens; lines 12 and 13, underscore the wordsvlNcivtonian Space elements of the mechanism and that the said Letters Patent should be read with thes corrections therein that the same may conform to the record of the case in the PatentI Olce.

Signed and sealed this 29th day of September, A. D., `1914.V

` R. F. WHITEHEAD,

Acting Commissioner of Patnta.

[SEAL] 

